Compressor



COMPRESSOR Fired sept. 17, 1925 2 Sheets-Sheet 1 April s, 1927.'

F. E. HOLMES COMPRESSOR Filed Sept. 17, 1925 2 sheen-sheet 2 Cil Patented Apr. 5, 1927.

unirse STA ...FRANK Hormis-scr Femmina, oVALrronNrA. Assignee cro BLooMrrnLn-,HoLi/ms PATENT s oiferficis..

consommer. or PAseDEN-e. CALIFORNIA. 'a QQRPORATION OF CALIFORNIA- s COMPRESSQR.

appuauon me@ september 17g-1592s. ,serial No. 56,1861.

presser which is etlicient in operation, llovv in first rcost and Which will not become out of order. @lo meet these demands, the comlpressor mustbe simple and sturdy in clonstruction and must be of proper desilgn. One example of the use of a compresser of lthis. requirement is in small refrigerating systems such asare used iin 'homes and small butcher shops and stores. Such small re li'rigerating systems employ ethyl 'chloride or sulph-iir dioxide as refrigerant. These gases `do not requirefhigh compression to function. y

An object of my invention is to provide a vcompres-sor Which is adapted `for compressloW pressures but may be constructed for high pressure use. e i

It is 'a further 'object oit-my invention to provide a` compressor of 'this character which is llovv vin first-'cost and `upkeep by virtue of litsy peculiar and novel design. lnmyinvention I provide a housing having a chamber `which is of semi-cylindrical cross section. ln this ychamber is placed piston which 'is sector shape and `Which is of la lcross section which is of less cylindrical extension than the cliamber. The piston and the housing are so connected that thepiston swings in lthe chamber of "the hc'iusing. Suitable valves are provided in the housing and vin vthe piston and the operation issuch that the device "compresses gas.

` lt is a further object of my invention to provide a' compressor of v,the character mentionedL Which is very 'simple and quite rugged in construction. It is another object of my invention to provide a compressor of this Character having avnovelfform of intake valve.

llt'is also an objectief my invention to lprorid'e a compressor of this character 'havingl a novel forni `of exhaust valve. The exhaust valve of my invention is very important to the operation of the compresso-L A cylin vdrical exhaust valve chamber is formed in lthe piston in which exhaust valve chamber is placed a valve of invention. This valve is yifriacle fron'i a sheet lwhich is rolled into cylindrical forni. 1t! is secured in the chamber Yin lsuch a manner that the valve portion thereof closing ports `in "the pistonis resiliently retained in lclose contact With the cylindrical Wallof the chamber.

. It is a still further object ofmy invention to provide a compressor having replaceable liners. These liners, 'when vvvorn, may be replaced by :new linersand "any play of-"the Working part-s `of the compressor may 'be cheaply .and readily removed. Y

I t `isal'so an object of my invent-ion toprovidea double acting compressor of the generali-type set Aforth heretofore.

A further object of my invention isto pro- -vi'dea compressor which may be vdirectly connected with amotor.

Other objects and the :particular `advanl:tages of `mH followingdescription. i

Referring' to the tivo sheets of drawings Whichare for illustrative `purposes only and in which I lillustrate a vpreferred form of my invention,

Fig. 1 iis a plan vv'ievv of 'a device Vemploying a compressor with the features of my invention.

Fig. 2 an elevational vievvof Fig. 1. Fig. 3 is an 'enlarged sectional view taken through a compressor yembodying the features of my invention.

Fig. 4 is a 'sect-iontaken on theiline 4-.4 of Fig. '3, and showing clearly in detail the exhaust valve construction of my invention. 5 is a perspective View of the exhaust valve of my invention. i y

Fig. 16 Yis a face view 4showing inI detail a diametral plate, van intake lvalve and aipivot bar of 'my invention. i 1

l/Vith particular reference to Figs. 3 to. 6. inclusive, ofthe drawings, the form of my v invention vill beset forth in the invention shown comprises a housing 11 y forming a piston chamber i12. The housing V11 consists `of a sen'iifcylindrical member 13, plates`1fl, and' a `dianietial plate 15. As clearly shovvn inFig. 3. the Semicylindrical member 13 has a semi-cylindrical face 17 which is `generatekil on an axis indicated atl 18 in Fig. e Placed in the chamber 12 and in engagement {Vith-the semi-'cylindrical face 17 of the .member 13 is a bushing` plate 19 which has an inner Vface Whichis 'concentric 'with the 18. This 'bushing` plate l19 is made from 'suitable bearing `metalsuch as phosphor-bronze. The end plates 14 are 'secured to faces 2O of the semi-cylindrical ice iio

member 13 by screws 21 which extend. into flanges 22 of the member 13. Gasket plates 23 are secured between the faces 2O of the member 13 and the end plates 14. These `gaskets 23 are made from a metal having high bearing qualities, such as phosphorbronze. The diametral plate is secured to faces 25 and 26 of the member 13 and the end plates 14 by screws 27 which extend into flanges 28 of the end plates 14 and into the ends of the wall of the member 13. A gasket plate 29 is secured between the member 13 and the diametral plate 15.

The gasket plate 29 has slots 30, as clearly shown in Fig. 6, forming an intake valve 31 which is adapted to close intake ports formed in the diametral plate 15.

A pivot bar 35 is secured inside the chamber 12 to the diametral plate 15 by screws 36. As clearly shown in Figs. 3 and 6. the pivot bar 35 ext-ends concentrically along the axis 18 of the chamber 12 and has a semi-cylindrical face 37 which is generated around the axis 18.

A bearing member 39 having cylindrical bearings 40 formed on the ends thereof is secured to the exterior of the diametral plate 15 bv screws 41. The bearing member 39 consists of a bar portion 44 having a cylindrical face. as shown, with which bar portion 44 the bearings 40 are integrally formed. The bearing member 39 is so situated that an axis extending through the cylindrical bearings 40 intersects the axis 18 and extends at right angles thereto. This is clearly shown in Fig. 3. The bearing member 39 is positioned so that the cylindrical bearings 40 are arranged centrally of the length of the chamber 12.

Journals 46 formed at the ends of arms 47 of a. yoke 48 are carried on the cylindrical bearings 40. The arms 47 have semi-cylindrical faces 49 which engage the outer portions of the bar 44. Openings 50 are formed near the ends of the arms 47 to permit an installing and removal of the screws 41` The bearing member 39 and the yoke 48 must be assembled before the bearing member 39 is secured to the housing 11. A motor shaft 53 is secured in a suitable manner in an opening 54 of a hub 55 of 'the yoke 48.

In the chamber 12 is a piston 60 from which there extends a piston shaft 61, this piston shaft 61 extending from the piston through openings 64 and 65 in the bushing 19 and the member 13. The piston 60 is sector shape in cross section having a semicylindrical face 68 which contacts 'the inner face of the bushing 19. End faces 69 of the piston 60 contact the inner faces of the bearing gaskets 23. The piston 60 has radial faces 71, as clearlyshown in Fig. 3. which are arranged to swing very close to the inner face of the gasket 29 as will be described later. At the apex of the faces 71 is formed a semi-cylindrical bearing channel 72 which engages the semi-cylindrical face 37 of the pivot bar 35. As clearly obvious from Fig. 3, the cross section of the piston 60 is of .less cylindrical extension than the chamber 12. There is, therefore,asegmentshaped cavity 73 left in the chamber 12 when the piston is in the position shown in Fig. 3.

Cylindrical exhaust valve chambers 74 are formed in the piston (i0 on an axis parallel to the axis 18 of the chamber 12. The ends of the bearing chamber 74 are closed by plugs 75 which are threadably secured in place, as shown clearly in Fig. 4. Exhaust ports 7G connect between the radial faces 7l and the valve chambers 74.

Cylindrical exhaust valves are secured in the chambers 74 by dowel screws 81. The heads of these dowel screws extend through openings in the valves 80 which spring into place. These cylindrical exhaust valves 80 are formed from a flat sheet 82 which is bent into cylindrical contour as clearly shown in Fig. The exhaust valves 80, as clearly shown in Figs. 3 and 4, extend around the circumference of the chambers 74 in engagement with the cylindrical walls thereof. Valve portions 83 of the valves 80 extend so as to close the exhaust ports 7 6. Tail portions 84 are provided to give a leverage for resiliently, yet forcibly, retaining the valve portions 83 in closing positions. A passage 86 connects with the cha1nbers 74 at a point between the tails 84. An exhaust passage 87 connects with the passage 86 and extends from the piston 60 through the piston shaft 61.

As clearly shown in Figs. 1 and 2, the shaft 53 extends through a motor 90 secured to a swingable base 91 which is pivotally mounted on a sub-base 92 by a pivot bolt 93. Teeth 94 are Jformed at the right hand end of the base 91 which are engaged by a. worm 95 supported by a shaft 96 which extends through bearings 97. A hand wheel 98 is secured to the end of the shaft 9G whereby this shaft is rotated in a manner to rotate the worm 95. A rotation of the worm by virtue of its engagement with the teeth 94 swings the base 91. This will be described shortly.

The piston shaft 61 extends through a journal 99 secured to the base 92 by bolts 100. A stuffing box 102 is placed on the cxtendinp; end 103 of the piston shaft (il, there being a pipe 105 extending from the stulling box 102 through which compressed gases pass. The piston shaft 61 has an annular channel 106 into which a tongue 107 of a member 108 carried by the journal 99 cxtends. This member 108 is provided for positioning the compressor.

The operation of my compressor may be clearly understood by considering the action `ofthe parts of a universal joint. The housing 11, the yoke48 `and the piston 60 move substantially the same manner as the main parts of a universal joint. AIt is necessary for the operation of the pump to have the shafts 53, and 61 outv of alignment so that therewill be a relative movement between the housing 411 and the piston 60. The `greater the vdisalignment kof the shafts 53 and 61, the greater the movement between the housing 11 and the piston 60, and'c0n jsequently al larger volumeuof gas may be n size land then increases t0 the sizeshown.

During this movement, a cavity of similar shape is formed between the lower radial face 71 and the gasketv plate 29, and when the cavity 7 3 is minute in size,a lower cavity `willibe formed which Iis of the sizeof the .cavity 73 shown in the drawings. W hen the cavity-`73 is decreasing in size, gas trapped ktherein is forcedthrough the exhaust ports 76, this gas forcing the valve portion83 awayfrom-the cylindrical wall of this chamber 74, thus `allowing it to be forced into this cylindrical exhaustvalve chamber 74.

As the cavity 7 3 increases in size, the `valve f 4portionf83 .returns into contact with the wall of this upperv exhaust valve chamber 74, closing `the :upper exhaust port 76. A suction at thistime is created in the cavity 73 whichvremoves the upper intake valve 31l from closing position, permitting gas to pass through the :upper intakes 32 and into lthe cav-ity 73. yAs the cavity 73v is again decreased in size, theoperation just described isvr'epeated Likewise, theV operation with the lower part of theco-mpressor is exactly Cil i (it)y thefsame as that just described with regard to the upper part. However, Vthe operation `is out of yphase and while the cavity 73 is deLk creasing in size, a lower-cavity is increasing in size and viceversa. From this description of the roperation' of the pump, it will be seen that my invention provides a double actingcompressor.

The gas passes from the vexhaust valve chamber 7 4through the passage 86, `thro-ugh tliepassager .87 and is conducted yfrom the shaft-161 by the fpipe 105 of the stutling box `102. By swinging the base 91, the shaft 53 may be moved so thatthe axis thereof extends at a smaller angle` to the axis of the shaft 61, thusdecreasmg the relative swinging movement yof the housing 11 and the piston 60. Vhen the shafts 53 and l61 are yin alignment, there will benorelative `movement 'betweenfthehousing and piston 11 and 60, respectively, and consequently there will be no relative movement between the housing andthe pistons 11 and 60, respectively, and there will be no pumping action.

Myinvention alsoprovides anovel means for lubricating the piston 60. With reifercnce to Fig. 3, Ythe end ofthe hub 55 is provided with `an annular oil recess 110 having a-lip formation 111. @il is introduced into `this recess 110 by any suitable means. The oil, by centrifugal force, is thrown to :the outer parts of the recess 110. The oil passes into-oil ducts 112 which diverge slightly, as shown in Fig. The'ducts extend radially outwardly `at 113 through the arms 47 `of the yoke 48. `Semi-cylindrical channels `114 are formed inthe portions 49'which are connected to the portions 113of the ducts 112 by portions 115 which extend substantially parallel to the axis Vof rotation of the `shaft 53. Holes 1116 are drilled through the bar member 44, these holes connecting with the semi-cylindrical channels 114 and with open ings 117 formed in the diametral plate 15. It will benoted in Fig. 3 that the ends of `the intake Avalves 31 cover these openings 4117. rTheoil passes through `th-e ducts 112 'by reason of centrifugal `force and passes im f into the openings 116 and 117. l/Vhen the i valves 31 are unseated, oil is drawn into a cavity by suction and provides lubrication between the walls of the piston 60 and the walls of the chamber 12. This system of lubrication is very efficient `and is entirely automatic in opera-tion.

.From the foregoing description it is obvious that my compressor differentiates from .the usual` compressor construction.

vide a pump which is eliicient .in operation and which is very sturdy and simple in construction. The compressor, as shown,.is de-y signed to be directly connected to a motor. i

rlhis is an'appreciable saving as it veliminates interconnecting mechanism. The parts lare' few .and are readily assembled together. The bushing 19 and the `gasket plates 23 and 29 may be replaced when they become worn, thus cheaply removing any lplay from the compressor. The cylindrical exhaust valves 30 of myfinvention are so designed that they operate effectively and efficiently.. They may be readily removed by removing one end plate 14 and a plug 75, which gives access to a chamber 74. i

I claim asmy invention:

1. In a device of the class described, the

combination of: a housing forming a cavity of semi-cylindrical cross section; a piston swmgably arranged 1n said cavity, said piston having a cylindrical exhaust valve chamber, an exhaust port connecting between This nov-el construction makes it possible to prosaid valve chamber anda radial face of said piston, and an exhaust passage connected to said valve chamber, there being a sectorshaped space between said radial face and a plane face of said housing, said sector-shaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same is enlarging; and a cylindrical exhaust valve engaging the cylindrical wall of said exhaust valve chamber and closing said exhaust port; said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size.

2. In a device of the class described, the combination of: a housing forming a cavity of semi-cylindrical cross section; a piston swingably arranged in said cavity; said piston having a. cylindrical exhaust valve chamber extending parallel to the axis ot said cavity, an exhaust port connecting between said valve chamber and a radial face of said piston; and an exhaust passage connected to said valve chamber, there being a sector-shaped space between said radial tace and a plane face of' said housing,` said sector-shaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same is' enlarging; and a cylindrical exhaust valve engaging the cylindrical wall of said exhaust valve chamber and closing said exhaust port, said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size.

3. In a device of the class described1 the combination of a housing forming a cavity of semi-cvlindrical cross section; a piston swingably arranged in said cavity, said piston having a cylindrical exhaust valve chamber, an exhaust port connecting between said valve chamber and a radial face ot' said piston, and an exhaust passage connected to said valve chamber, there being a sectorshaped space between said radial face and a plane face of said housing, said sector-shaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same is enlarging; and an arcuate exhaust valve engaging the cylindrical wall of said exhaust valve chamber and closing said exhaust port` said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size.

el. In a device of' the class described, the combination of: a housing forming a cavity of semi-cylindrical cross section; a piston swingably arranged in said cavity, said piston having a cylindrical exhaust valve chamber, an exhaust port connecting between said valve chamber and a radial face of said piston, and an exhaust passage connected to said valve chamber, there being a sector-shaped space between said radial face and a plane face of' said housing, said seetor-shaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same is enlarging; and an exhaust valve for closing said exhaust port, said exhaust valve allowing fluid to pass 'through said exhaust port when said space is decreasing in size, said valve operating in a radial direction relatively to the axis of said exhaust valve chamber.

5. In a device of the class described, the combination oli: a housing forming a cavity of semi-cylindrical cross section; a piston swingably arranged in said cavity; .f-:aid piston having a cylindrical exhaust valve chamber, an exhaust port connecting between said valve chamber and a radial face oi said piston, and an exhaust passage connected to said valve chamber, there being a sector-shaped space between said radial 'tace and a plane face of' said housing, said sectorshaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same enlarging; and a c vlimlrical exhaust valve engaging the cylindrical wall of said exhaust valve chamber and closing said exhaust port, said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size, said valve operating in a radial direction relatively to said exhaust valve chamber.

6. In a device of the class described, the combination of: a housing forming a cai-it)v of semi-cylindrical cross section; a piston swingably arranged in said cavity, said piston having a cylindrical exhaust valve chamber` an exhaust port connecting between said valve chamber and a radial face of said piston, and an exhaust passage connected to said valve chamber, there being a sector-shaped space between said radial face and a plane face ot' said housing; said sectorshaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same is enlai-ging; and an arcuate exhaust valve engaging the cylindrical wall of said exhaust valve chamber and closing said exhaust port; said exhaust valve allowing fluid to pass through saidfexhuust port when said space is decreasing in size; said valve. operating in a radial direction relatively to the axis of said exhaust valve chamber.

7. In a device of the class described, the combination of: a housing forming a cavity of semi-cylindrical cross section; a piston swingably arranged in said cavity, said piston having an exhaust valve chamber.y an exhaust port connecting between said valve chamber and a radial face of said piston. and an exhaust passage connected to said valve chamber7 there being a sector-shaped space between said radial face and a plane lll() lll! said spa-ce when saine is enlarging;

Lenawee.

f'ace of said housing, said sector-shaped space changing in size as said piston is` swung.; an intake valve throughvwhich fluid enters said spacey when sanie kisv enlarging; an exhaust valve for closing said exhaust port, said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size; and a yoke pivoted to said housing.V

8. In a? device of the class described, the combination of: aliousing forming acavity ot seini-cylindrical crossV section; a'piston swingably arranged in saidl lcavity, said piston having an exhaust valve chamber, an exhaust port connecting between said valve chamber and a radialface of said'piston,xand an exhaust passage connected to said valve chamber, there being La sector-shaped space between said, radial face and a plane face of" said housing, said' sector-shaped spacechanging in. size as said piston is swung; an` intake valvethrough which fluid enters an exhaustr valve for closing said exhaust' port;

said exhaust valve allowing fluid to pass` through said exhaust port when said space is decreasing in size;and ayoke pivoted to said housing on an axis at` right angles to the axis on which saidv piston swings.

9. In ay device ofthe class described, the combinationv :of I:y a housing forming la `cavity of semi#cylindricalk vcross section; a piston swingably arrangedin said cavity, said pis-y ton having` aniexhaustqvalve chamber, an eiliausty port `connecting between said valve chamber anda radiaflface `of said piston, and an exhaust passagel lconnected' to said valve chamber, -there being sector-shaped space betweensaid radial#face` andfa plane face of said housing, 'said sectonshaped space changing` in size yaslsaid4 piston is sn-'ungg an `intaker valvev `through which fluid enters said` space when saine is enlarging; anexhaust valve for. closingsaid exhaust port, said'v exhaust valve allowingy fluid to pass through said exhaust port when said spacefis decreasing in size; and a yoke pivoted to. said housing on an axis lat right angles, to and intersecting the axis yon which said piston swings.

i A l0. In a device of the Iclassdfes'cribed, the

combination of a housingformingr a cavity Of seniiscyiindrical cross section; a Vpiston sw'ingably arranged yiny said cavity, lsaid piston having an exhaust valve chamber, an exhaust port connecting between said valve chamber and a radial face-'of said piston, and an exhaust passage connected to said valve chamber, there being a sector-shaped space between said radial face and a plane face of rsaid housing, said sector-shaped space changing in size ras said vpiston is swung; plugs for closing the ends of said exhaust valve chamber; an intake valve through which fluid enters said space when ysanne is enlarging; and an exhaust valve for closing said exhaust port, said exhaust valve allowing fluid tol pass through said exhaust port when said space is decreasing in size.'y

ll, Ina device of the class described, the combination of: -a housing forming a cavity of seiniylindrical cross section; a piston. swingably arranged in lsaid cavity, said piston having a cylindrical exhaust valve chainber,l an exhaust port connecting between said valve chamber and a radial face ofsaid piston, and lan exhaust passagev connected to said .valvechamberf,there being a sectorshaped space between said radiali face and a plane face of said housing, said sectorshaped space changing in size asY said piston is swung;vplugs for closing the ends of said exhaust valve chamber; anv intake'y valve through which fluid lenterssa'id space when saine is enlarging; and an exhaust valve for closing said exhaust port, said exhaust valve allowing fiuid to pass through saidfexhaust port when said space is decreasing in size. Y

1Q. In la device of the class described, the combination of: la. housing forming a cavity of` semin'cylindrical' cross section; a piston swingably arranged in said cavity; saidApis-` ton having a cylindrical exhaust valve chain:l ber, an exhaust port connecting between said valve chaniberand ara'diral face of said piston, land an exhaust passage connected' to said valve chamber; there being a. ysectorshfap'ed space between said radial face and a planel face of said housing, `said sectorshaped space changing'in :sizeas said piston is swung; `plugs for closingv the ends ofsaid exhaust valve chamber;` an intake valve throughwhich fluid enters said space when saine is enlarging; and a cylindricalexhaust valve kengaging the cylindrical wail of `said exhaust valve chaniber and closing said ex haust port, said exhaust valve allowing fluid to pass through said exhaust port when said spaceis decreasing in size.

*3, In a device 'of the class described; the ccn'abination of.: a housing forming a cavity ot senii-cylindrical cross section; `a piston sniifng'ably arranged in said cavity, Vsaid piston having u,an exhaust valve chamber, an

exhaust porty connecting between said valve chamber anda radial face oft sai-d piston, and an exhaust passage connected to said .valve chamber, there being a sector-shaped space between said radiali-ace anda pflane face of said housing, said sector-shaped space chang-ing in size as saidV piston is swung; an intake valve through which iuidenters said space when saine is enlarging; an exhaust valve for closing said exhaust port, Vsaid exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size; a yoke pivoted to said housing on an axis at right ang-les to the axis on which said piston swings; a yoke shaft extending from said yoke; and a piston vshaft extending from said piston to the exterior of said housing.

14. In a device of the class described, the combination of: a housing forming a cavity of semi-cylindrical cross section, said housing including a diametral plate having intake ports therein; a piston swingably arranged in said cavity, there being a sectorshaped space between a face ot' said piston and said diametral plate, said sector-shaped space changing in size as said piston is swung; an exhaust valve carried by said piston; and an intake valve adapted to open and close said intake ports.

15. In a device et the class described, the combination ot: a housing forming a cavity ol semi-cylindrical cross section, said housing including a diametral plate having intake ports therein; a piston swingably arranged in said cavity, there being a sectorshaped space between a face of said piston and said diametral plate, said sector-shaped space changing in size as said piston is swung; an exhaust valve carried by said piston; and an intake valve adapted to open and close said intake ports, said intake valve comprising a gasket plate adapted to close said intake ports when said space is decreasing in size and to open said ports when said space is increasing in size.

16. In a device of the class described, the combination of: ahousing forming a cavity of semi-cylindrical cross section, said housing including a diametral plate having intake ports therein; a piston swingably arranged in said cavity, there being a sectorshaped space between a face of said piston and said diametral plate, said sector-shaped space changing in size as said piston is swung; an exhaust valve carried by said piston; and an intake valve adapted to open and close said intake ports, said intake valve comprising a. gasket plate adapted to close said intake ports when said space is decreasing in size and to open said ports when said space is increasing in size, there being slots in said gasket plate allowing passage of Huid to the said space when said intake ports are open. A

. 17. In a device of the class described, the combination of: a housing forming a cavity of semi-cylindrical cross section, said housing including a diametral plate having intake ports therein; a piston swingably arranged in said cavity, said piston having an exhaust valve chamber, an exhaust port connecting between said valve chamber and a radial face of said piston, and an exhaust passage connected to said valve chamber. there being a sector-shaped space between said radial face and the diametral plate, said space changing in size as said piston is swung; an intake valve adapted to open and close said intake ports by which fluid enters said space when saine is enlarging; and an exhaust valve for closing said exhaust port, said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size.

1S. In a device ot the class described, the combination of: a housing forming a cavity ot semi-cylindrical cross section; a bushing plate lining the seini-cylimlrical portion ol: said housing. thereby partly delining said cavity; a piston swingably arranged in said cavity, said piston having an exhaust valve chamber, an exhaust port connecting between said valve chamber and a. radial face ot' said piston, and an exhaust passage connected to said valve chamber, there being a sector-shaped space between said radial face and a plane face of said housing, said sector-shaped space changing in size as said piston is swung; an intake valve through which fluid enters said space when same is enlarging; and an exhaust valve for closing said exhaust port, said exhaust valve allowing fluid to pass through said exhaust port when said space is decreasing in size.

19. In a device ot' the class described, the combination of: a housing forming a cavity of semi-cylindrical cross section; a bushing plate lining the semi-cylindrical portion ot' said housing thereby partly defining said cavity; a piston swingably arranged in said cavity, the sides ot' said piston engaging the said bushing plate lining; intake valves conimunicating with said cavity; and exhaust valves comn'iunicating with said cavity.

S20. In a device of the class described, the combination of: a housing 'forming a cavity ol semi-cylindrical cross section. said housing including a flat diametral plate having inlet ports therein; a. piston s\\'ingably arranged in said cavity; an intake valve co1nmunicating with said cavity, said valve comprising a gasket plate adapted to open and close said inlet ports; and an exhaust valve communicating with said cavity.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 12th day ot Sept., 1925.

FRANK E. JIOLUES. 

